<?php 

/*
    // $ 表示的是声明变量的意思
    // php 是解释性语言，编译语言，非强类型
    $value = 100;
    echo $value."<br/>";
    
    $value = "string";
    echo $value."<br/>";

    $value = 10.10;
    echo $value."<br/>";

    $value = null;
    $value = 90;
    echo $value."<br/>";

    $value = false; // nullptr
    echo $value."<br/>";
    $value = true; // 1
    echo $value."<br/>";

    $value = true;
    if($value == 1){
        $value = false;
        echo "value = true"."<br/>";
    }
    
    $value = false;
    if($value == 0){
        echo "value = 0"."<br/>";
    }
    if($value == null){
        echo "value = null"."<br/>";
    }else{
        echo "value = false"."<br/>";
    }

    echo '"hello world" $value';

    print("<br/>hello world");
    printf("<br/>hello world");
    // substr()
    // md5()
    // ......
*/


$value = 1;
if($value = 1)
    echo "<img src='./image.png'>"."<br/>"; // img 里面的双引号可以改成单引号
else
    echo "<audio src='./故事还长.mp3' controls loop>音乐</audio>"."<br/>";


$count = 10;
while($count > 0){
    $count--;
    echo "hello world"."<br/>";
}

echo "<br/>";
do{
    $count++;
    echo "hello world"."<br/>";
}while($count < 10);

echo "<p>WampServer: Apache Web、MySQL、PHP </p>";


